Structure of the Sec61 channel opened by a signal sequence

Seeing the signal sequence in action Protein translocation across the endoplasmic reticulum (ER) involves the interaction of a signal sequence with the protein translocation channel. Although much work has looked at the details of protein translocation, questions remain. Voorhees and Hegde present a single-particle cryoelectron microscopy study of the mammalian ER translocation apparatus at the point in which the signal sequence is engaging the translocation pore. Science , this issue p. 88